diff --git a/.github/workflows/docker-image.yml b/.github/workflows/docker-image.yml
index c5f13ca..3f3cffa 100644
--- a/.github/workflows/docker-image.yml
+++ b/.github/workflows/docker-image.yml
@@ -1,35 +1,134 @@
 ---
+
 name: Docker Image CI
 
 on: # yamllint disable-line rule:truthy
   push:
-    branches: [main, develop, feature/*]
+    branches: ["main", "develop", "feature/*"]
   pull_request:
-    branches: [main]
+    branches: ["main"]
 
-permissions: read-all
+env:
+  IMAGE_NAME: algorithm-exercises-csharp
+  ARTIFACT_NAME: algorithm-exercises-csharp_${{ github.sha }}
 
 jobs:
+
   build:
-    name: Build & Test in Docker
+    name: "Build Docker images"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
 
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: "LINT: Build and push"
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          target: lint
+          outputs: |
+            type=docker,dest=/tmp/${{ env.ARTIFACT_NAME }}_lint.tar
+          tags: |
+            ${{ env.IMAGE_NAME }}:lint
+      - name: "LINT: Upload artifact"
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ env.ARTIFACT_NAME }}_lint
+          path: /tmp/${{ env.ARTIFACT_NAME }}_lint.tar
+
+      - name: "TEST: Build and push"
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          target: testing
+          outputs: |
+            type=docker,dest=/tmp/${{ env.ARTIFACT_NAME }}_test.tar
+          tags: |
+            ${{ env.IMAGE_NAME }}:test
+      - name: "TEST: Upload artifact"
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ env.ARTIFACT_NAME }}_test
+          path: /tmp/${{ env.ARTIFACT_NAME }}_test.tar
+
+      - name: "PRODUCTION: Build and push"
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          target: production
+          outputs: |
+            type=docker,dest=/tmp/${{ env.ARTIFACT_NAME }}_prod.tar
+          tags: |
+            ${{ env.IMAGE_NAME }}:latest
+            ${{ env.IMAGE_NAME }}:${{ github.sha }}
+      - name: "PRODUCTION: Upload artifact"
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ env.ARTIFACT_NAME }}_prod
+          path: /tmp/${{ env.ARTIFACT_NAME }}_prod.tar
+
+  lint:
+    name: "Run in docker: LINT"
     runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Download artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ env.ARTIFACT_NAME }}_lint
+          path: /tmp/
+
+      - name: Load image
+        run: |
+          docker load --input /tmp/${{ env.ARTIFACT_NAME }}_lint.tar
+          docker image ls -a
+
+      - name: Run lint
+        run: |
+          docker run --rm ${{ env.IMAGE_NAME }}:lint make lint
 
+  test:
+    name: "Run in docker: TEST"
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Download artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ env.ARTIFACT_NAME }}_test
+          path: /tmp/
+
+      - name: Load image
+        run: |
+          docker load --input /tmp/${{ env.ARTIFACT_NAME }}_test.tar
+          docker image ls -a
+
+      - name: Run test
+        run: |
+          docker run --rm ${{ env.IMAGE_NAME }}:test make test
+
+  security:
+    name: "Snyk Container"
+    runs-on: ubuntu-latest
+    needs: build
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
     steps:
       - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
-      - name: Build the Docker image
-        run: make compose/rebuild
-      - name: Lint in Docker image
-        run: make compose/lint
-      - name: Test in Docker image
-        run: make compose/test
-      - name: Run in Docker image
-        run: make compose/run
-      - name: Tag Docker image
-        run: >
-          docker tag
-          algorithm-exercises-csharp:latest
-          algorithm-exercises-csharp:${{ github.sha }}
+      - name: Download artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ env.ARTIFACT_NAME }}_prod
+          path: /tmp/
+
+      - name: Load image
+        run: |
+          docker load --input /tmp/${{ env.ARTIFACT_NAME }}_prod.tar
+          docker image ls -a
 
       - name: Run Snyk to check Docker image for vulnerabilities
         # Snyk can be used to break the build when it detects vulnerabilities.
@@ -44,11 +143,47 @@ jobs:
           # yamllint enable rule:line-length
           SNYK_TOKEN: ${{ secrets.SNYK_TOKEN }}
         with:
-          image: algorithm-exercises-csharp:latest
+          image: ${{ env.IMAGE_NAME }}:${{ github.sha }}
           args: --file=Dockerfile
-    # yamllint disable rule:comments-indentation
-    # - name: Upload result to GitHub Code Scanning
-    #   uses: github/codeql-action/upload-sarif@v2
-    #   with:
-    #     sarif_file: snyk.sarif
-    # yamllint enable rule:comments-indentation
+      # yamllint disable rule:line-length
+      # https://github.com/github/codeql-action/issues/2187#issuecomment-2043220400
+      - name: Replace security-severity undefined for license-related findings
+        run: |
+          sed -i 's/"security-severity": "undefined"/"security-severity": "0"/g' snyk.sarif
+          sed -i 's/"security-severity": "null"/"security-severity": "0"/g' snyk.sarif
+      # yamllint enable rule:line-length
+      - name: Upload result to GitHub Code Scanning
+        uses: github/codeql-action/upload-sarif@v3
+        with:
+          sarif_file: 'snyk.sarif'
+  scan:
+    name: "Trivy"
+    runs-on: ubuntu-latest
+    needs: build
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+    steps:
+      - name: Download artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ env.ARTIFACT_NAME }}_prod
+          path: /tmp/
+
+      - name: Load image
+        run: |
+          docker load --input /tmp/${{ env.ARTIFACT_NAME }}_prod.tar
+          docker image ls -a
+
+      - name: Run Trivy vulnerability scanner
+        uses: aquasecurity/trivy-action@0.24.0
+        with:
+          image-ref: ${{ env.IMAGE_NAME }}:${{ github.sha }}
+          format: 'sarif'
+          output: 'trivy-results.sarif'
+
+      - name: Upload Trivy scan results to GitHub Security tab
+        uses: github/codeql-action/upload-sarif@v3
+        with:
+          sarif_file: 'trivy-results.sarif'
diff --git a/Dockerfile b/Dockerfile
index b7e2387..9fca5ae 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,11 +1,25 @@
 ###############################################################################
-FROM mcr.microsoft.com/dotnet/sdk:8.0.302-1-alpine3.19-amd64 AS base
+FROM mcr.microsoft.com/dotnet/sdk:8.0.302-1-alpine3.19-amd64 AS init
 
 ENV WORKDIR=/app
 WORKDIR ${WORKDIR}
 
 RUN apk add --update --no-cache make
 
+###############################################################################
+FROM init AS base
+
+ENV WORKDIR=/app
+WORKDIR ${WORKDIR}
+
+COPY ./Makefile ${WORKDIR}/
+COPY ./algorithm-exercises-csharp.sln ${WORKDIR}/algorithm-exercises-csharp.sln
+COPY ./algorithm-exercises-csharp/algorithm-exercises-csharp.csproj ${WORKDIR}/algorithm-exercises-csharp/algorithm-exercises-csharp.csproj
+COPY ./algorithm-exercises-csharp-base/algorithm-exercises-csharp-base.csproj ${WORKDIR}/algorithm-exercises-csharp-base/algorithm-exercises-csharp-base.csproj
+COPY ./algorithm-exercises-csharp-test/algorithm-exercises-csharp-test.csproj ${WORKDIR}/algorithm-exercises-csharp-test/algorithm-exercises-csharp-test.csproj
+
+RUN make dependencies
+
 ###############################################################################
 FROM base AS lint
 
@@ -35,7 +49,6 @@ COPY ./algorithm-exercises-csharp ${WORKDIR}/algorithm-exercises-csharp
 COPY ./algorithm-exercises-csharp-base ${WORKDIR}/algorithm-exercises-csharp-base
 COPY ./algorithm-exercises-csharp-test ${WORKDIR}/algorithm-exercises-csharp-test
 COPY ./algorithm-exercises-csharp.sln ${WORKDIR}/algorithm-exercises-csharp.sln
-COPY ./Makefile ${WORKDIR}/
 
 # code linting conf
 COPY ./.editorconfig ${WORKDIR}/
@@ -56,7 +69,6 @@ COPY ./algorithm-exercises-csharp ${WORKDIR}/algorithm-exercises-csharp
 COPY ./algorithm-exercises-csharp-base ${WORKDIR}/algorithm-exercises-csharp-base
 COPY ./algorithm-exercises-csharp-test ${WORKDIR}/algorithm-exercises-csharp-test
 COPY ./algorithm-exercises-csharp.sln ${WORKDIR}/algorithm-exercises-csharp.sln
-COPY ./Makefile ${WORKDIR}/
 
 RUN make build
 RUN ls -alh